The United States military has secretly sent a task force of more than 150 planners and other specialists to Jordan

To help the armed forces there handle a flood of Syrian refugees, prepare for the possibility that Syria will lose control of its chemical weapons and be positioned should the turmoil in Syria expand into a wider conflict.

The task force, which has been led by a senior American officer, is based at a Jordanian military training center built into an old rock quarry north of Amman. It is now largely focused on helping Jordanians handle the estimated 180,000 Syrian refugees who have crossed the border and are severely straining the country’s resources.

American officials familiar with the operation said the mission also includes drawing up plans to try to insulate Jordan, an important American ally in the region, from the upheaval in Syria and to avoid the kind of clashes now occurring along the border of Syria and Turkey.

The officials said the idea of establishing a buffer zone between Syria and Jordan — which would be enforced by Jordanian forces on the Syrian side of the border and supported politically and perhaps logistically by the United States — had been discussed. But at this point the buffer is only a contingency.